This was a specific purchase for my Doublevision 'bent-tandem. After 11 years, I had worn out the previous chainring(s), and am replacing all of them. This is primarily in anticipation of extreme use, i.e., my trans-Texas bicycle tour, 11JUN-25JUL2011, El Paso to Orange and back. Going East, I will mostly stay South of I10; returning West, I will mostly stay North or on I10. As of right now, all of my rebuild is going well. I'll give an update after completion. [@]